Electronic parking brake system and control method thereof

Abstract

An electronic parking brake system including: an electronic parking brake including a pair of brake pads disposed on both sides of a brake disc rotating with a rear wheel of a vehicle, a piston provided to press the pair of brake pads, a nut member provided to press the piston, a spindle member provided to move the nut member, and a motor configured to rotate the spindle member; and a controller electrically connected to the motor and configured to perform a parking operation for the EPB, wherein the controller is configured to detect an inrush current flowing through the motor during the parking operation, and identify a low voltage fault based on the detected inrush current.

What is claimed is: 
     
       1. An electronic parking brake system, comprising:
 an electronic parking brake (EPB) comprising a pair of brake pads disposed on both sides of a brake disc rotating with a rear wheel of a vehicle, a piston provided to press the pair of brake pads, a nut member provided to press the piston, a spindle member provided to move the nut member, and a motor configured to rotate the spindle member; and 
 a controller electrically connected to the motor and configured to perform a parking operation for the EPB, 
 wherein the controller is configured to detect an inrush current flowing through the motor during the parking operation, and identify a low voltage fault based on the detected inrush current. 
 
     
     
       2. The electronic parking brake system of  claim 1 , wherein the controller is configured to identify the low voltage fault based on the detected inrush current and a driving voltage of the controller. 
     
     
       3. The electronic parking brake system of  claim 2 , wherein the controller is configured to identify as the low voltage fault if the driving voltage of the controller is higher than a preset voltage and the detected inrush current is lower than a minimum inrush current. 
     
     
       4. The electronic parking brake system of  claim 3 , wherein the controller is configured to identify the minimum inrush current according to the driving voltage of the controller. 
     
     
       5. The electronic parking brake system of  claim 4 , wherein the controller is configured to identify the minimum inrush current depending on the driving voltage of the controller, based on driving voltage-minimum inrush current mapping data stored in a memory. 
     
     
       6. A control method of an electronic parking brake system comprising an EPB comprising a pair of brake pads disposed on both sides of a brake disc rotating with a rear wheel of a vehicle, a piston provided to press the pair of brake pads, a nut member provided to press the piston, a spindle member provided to move the nut member, and a motor configured to rotate the spindle member; and a controller electrically connected to the motor and configured to perform a parking operation for the EPB, the control method comprising:
 detecting an inrush current flowing through the motor during the parking operation; and 
 identifying a low voltage fault based on the detected inrush current. 
 
     
     
       7. The control method of  claim 6 , wherein the identifying of the low voltage fault comprises identifying the low voltage fault based on the detected inrush current and a driving voltage of the controller. 
     
     
       8. The control method of  claim 7 , wherein the identifying of the low voltage fault comprises identifying as the low voltage fault if the driving voltage of the controller is higher than a preset voltage and the detected inrush current is lower than a minimum inrush current. 
     
     
       9. The control method of  claim 8 , wherein the identifying of the low voltage fault comprises identifying the minimum inrush current according to the driving voltage of the controller. 
     
     
       10. The control method of  claim 9 , wherein the identifying of the low voltage fault comprises identifying the minimum inrush current depending on the driving voltage of the controller, based on driving voltage-minimum inrush current mapping data stored in a memory.